For some time now I own a Kenwood TS-870S.
I have been playing around with the service menu on this rig for a
while. The information on this menu is scarce and people are usually
afraid to tweak this menu.

What you are about to read is pratical information on the TS-870S
service menu that may help you to take better advantage of this rig.
Before start reading this information please note the following:

I don't work for Kenwood and they didn't gave me any information.

The information on this article *can* cause damage to your radio.

The information on this article *will* void the warranty of your rig.

Before your TS-870S leaves the factory, Kenwood has aligned your rig (I hope they also did that to mine!). If it's working properly *do not* tweak the service menu.

I will not be held responsible *in any way* for damage that you do to your TS-870S. Use this information *at your own risk*.

I'm sorry, but I had to say this.
Now, let's start.

The TS-870S service menu has 28 items. Each of this items has a function and each function will allow you to control different parts of your rig.

Each menu has a hexadecimal identification (from A0 to BB).

All this items are stored in a EEPROM that is read each time you turn on your TS-870S.

The service menu allows you to change the settings of this EEPROM by writing data on it.

You can acess the service menu on your TS-870S by doing this:
Turn off the radio (using the [POWER] buttom).
Press, *at the same time* the [N.R.] and the [LSB/USB] buttons.
*While pressing* [N.R] and [LSB/USB] turn on your rig by pressing the [POWER] button.
The "Hello" message will appear on the display.
You can realease the [N.R.] and the [LSB/USB] button when you see the "Hello" message.
You should enter the service menu.

To leave the service menu and to return your rig to the "normal" operating condition, you can do this:
press the [CLR] button *or* turn off your rig by pressing the [POWER] button, and then turn it back on by pressing *only* the [POWER] button again.

If you are unable to enter the service menu of your rig read the instructions above again and do each step slowly.

*VERY IMPORTANT*
Before tweaking *any menu* make a clean register of *all* the values on each menu. This way, if you mess up something, you can allways go back by using the original value.
To do this, grab a piece of paper and once inside the service menu use the [M.CH/VFO.CH] button to go through the menus one by one.
*Do not touch any other button!*.
Start with A0 and make a note of what you see. Turn [M.CH/VFO.CH] clockwise and you will go to A1. Make a not of A1. Repeat this procedure for all the items until you reach item BA. Item BB is impossible to copy (you will see why when you are there).WARNING: *Do not* skip this procedure.
Another thing: I have found that different radios use different values, and this makes sence since there are *allways* slight differences in similar equipments.

Now, let's see what each item is for.

A0 - System

This menu will give you the EEPROM checksum. The TS-870S service manual says that it's the "Program Version Confirmation".
On my TS-870S, it reads:

FccA CHECK S

This menu can not be changed using any key on the front panel of your TS-870S and it will not affect the performance of your equipment.
Older rigs may have different values for the EEPROM checksum. To my Knowledge this is the lastest firmware version available to the 870S.
Some hams have reported that major DSP upgrade was made to the 870S before the release of this EEPROM version. Any comments?

A1 - ALC

This is a sensitive item and it will adjust the reference voltage the microphone ALC.
If you take a look at the service manual, the correct procedure for adjusting this menu is to connect a well calibrated digital volt meter to test point 2 (TP2) on the RF board (X44-3210-00) (A/9).
When measuring TP2 on the RF board the correct value will be 2.70V.
To adjust this value use the [RIT/XIT] button.
In my case, measuring TP2 for 2.70V lead me to a value of 89.
Your rig may lead you to other value. By the way, to measure TP2 you will have to remove the bottom cover of you rig. I advise you not to.
So the original reading on my 870S was:

A1 89 89 ALC REF

But, I am not using 89. After trying out different values for the ALC I felt confortable with FF.
To change to FF do this: turn [RIT/XIT] clockwise until you get this:

A1 FF 89 ALC REF

A1 is the menu number; FF is what you want; 89 is the original value;
ALC REF is the description of the A1 menu.
Now, we want to keep the FF value. By pressing the [UP] key you will get this:

A1 FF FF ALC REF

So you transfered the value you want (FF) and placed it over (89).
89 is no longer valid but it's not saved yet.
If you want to save this value for good, you will have to go into menu BA (use the [M.CH/VFO.CH] key) and press the [UP] key to save *all* the new information into the EEPROM.
After saving the info on the EEPROM turn your rig off using the [POWER] button. Turn it on again (use the [POWER] button) so the new settings can be read from the EEPROM.

When I said "*all* the new information" I mean that each and every menu that you have changed will be saved.
My advice is: change one item at a time and try out that item in particular. If not happy, go back to the original value.

In my case FF led me to a louder audio an to less shack noise into the microphone. Something that might be to worry is that fact that for the FF value, the reference voltage will be higher than 2.70V. I don't know
how much higher because I haven't measured it but I have been working with this value for quite some time and *my* rig works fine.

Ayway, let's supose that you are unhappy with FF an you want to go back to the original 89 value.

Just do this: go into menu A1 and turn [RIT/XIT] conterclockwise until you get this:

A1 89 FF ALC REF

Press the [UP] key and you will get:

A1 89 89 ALC REF

Now go to menu BA and press the [UP] key to record changes into the EEPROM. Now turn off the rig and turn it on again and you're back to the original setup. Easy, right?

A2, A3 and A4 - S-meter (SSB)

The S-meter was the reason that made me tweak the service menus in the first place.
On it's factory configuration my rig's s-meter was (most of the time) way bellow signal 9. Even with AM broadcast stations running several kilowatts I was unhappy with it because it was very difficult to go over 9, into the red area where 9+20, 9+40 and 9+60 dBs signals are located.
To adjust *properly* the s-meter you will need to generate some voltages. They are: -107dBm (yes, this is a voltage! It's just expressed in different units) for signal strenght 1. Then you'll need -81dBm for a 9 signal. Finally -23dBm for a full scale signal.
This voltages are in the range of a few microvolts. After all that is what we get from our HF antennas.
This voltages will have to enter the rig trough the antenna connector.
Keep in mind that if you try higher voltages in this input you will damage your rig.
Some hams out there have bench equipment capable of generating this voltages. Most of us can't do this, so here is what I did to adjust my s-meter:
The original values on my 870S were:

A2 xx 05 S.SSB.S1
A3 xx 60 S.SSB.S9
A4 xx 80 S.SSB.FUL

You can take a look at this values by going into menu number A2, A3 and A4. If you leave the antenna on and you have your rig on a SSB signal (any band is ok) you will see that the left numbers (above marked xx) will allways vary. This is normal and it's just your s-meter varying.
Since we want to get stable numbers on the left xx so we can copy this numbers into the right side (on top off 05, 60 and 80) we would need to disconnect the antenna and inject the user controled microvolt voltages until we have what we want.
The problem is the lacking voltage generator.
Here is a work around: connect a 50 ohm dummy load into the antenna connector. Turn the [RF] button fully clockwise.
If you are away from strong RF fields, now your readings must be:

A2 00 05 S.SSB.S1
A3 00 60 S.SSB.S9
A4 00 80 S.SSB.FUL

In my rig weak signals were fine, so I left A2 alone and I changed only A3 and A4.
I placed 30 in A3. You can do this by going into menu A3 and turning the [RF] button *slowly* conterclockwise until you have this:

A3 30 60 S.SSB.S9

Now, just press [UP] and you will get this:

A3 30 30 S.SSB.S9

For A4 I used a value of 60. So, using the same procedure, just get this:

A4 60 80 S.SSB.FUL

then press up and you have

A4 60 60 S.SSB.FUL

To save your changes go into menu BA and press [UP].
Now your s-meter will be much more sensitive and you will give better signal reports. :-)
Please notice what I said before. This is not a scientific way of calibrating the s-meter. The right way to do it is to generate the right voltages and place them into the antenna connector on the radio.
This is just a rough aproach that worked well in *my* case.

A5 and A6 - Filter

I haven't messed up with this so I can't help you here.
Anyway if you want to change this on your own (and tell me about it latter on) here are the original values on *my* rig and the keys for changing this values:

A5 00 00 8.83 FIL
A6 00 00 455 FIL

The [RIT/XIT] button will change the 00 left values between -99 and 99.
The [UP] key will place the left number into the right number.
Pressing [UP] on the BA menu will save your changes.

I have spoke to a great deal of TS-870S owners and just a few had made changes into the filters on this rig by placing in good quality filters (INRAD filters for example) instead of the stock filters. While the reports on the increase selectivity of rig seem to be true, I have been advised that the transmisson audio will loose quality because the TX bandwith will decrease.
Any info or comment on this subject is welcome.

A7 to AA - Power adjustment

Rumours say that this rig can go up to 150W.
My first comment on this: *if* it is capable of that and if you care about you radio *do not* increase the power to 150W. I think that you can damage the finals.
In it's factory configuration my TS-870S maximum SSB power was 95W.
I pushed the power a little higher into 110W (for driving my 2x3-500Z HF amp).
You will need a *calibrated* HF watt meter to do this. A Bird 43 will do just fine. Other calibrated HF meters will do.
Connect the power meter to the antenna connection of your rig. Then connect a 50 ohm dummy load *capable of handling more than 150W* to the power meter.
Go into A7. Press [SEND] and using [RIT/XIT] calibrate for 100W or your meter. When you're done press [SEND] again to stop transmitting.
The usual [UP] key will upgrade your value into the left number.
Going into BA and pressing [UP] will save your settings.

Before saving A7 I would advise you to ajust A8, A9 and AA. The procedure is identical. Make sure that you adjust A8 for 50W; A9 for 25W and AA for 11W (no, it's not a bug. I read "11W" on the service menu. If it's 10W and not 11W then the service manual has a bug!).

Then go to BA and save your changes.

AB to B3 - TX gain

If you adjusted the power off your rig you should also adjust this menus.
AB to B3 will adjust the TX gain on each band:

*WARNING*: I haven't found a way to return the settings on this menus to their original factory values. Actually I don't think there is a procedure for that. If you know how to this please contact me.
So, be carefull tweaking this menus. Once they are changed, *there is no turning back*.
Here's how to adjust the TX gain for menu AB. The procedure is the same for all the other menus (AB to B3).
Go into menu AB. You should see something like this:

AB 61 61 TxG 1.9M

Make sure you have a 50 ohm dummy load connected to your rig's antenna input.
Now, press [SEND]. You will see the left number changing. When the adjustment is complete you will ear a beep. Press the [SEND] key to stop transmitting into the dummy load. The left number must have changed. Supose that now you have:

AB 72 61 TxG 1.9M

Now press the [UP] key to get the number into the right side. This is what you get:

AB 72 72 TxG 1.9M

Go to BA and save the data by pressing the [UP] key, but do this after ou have adjusted the TX gain for all the bands.
If you try this I would like to know about your results. I tried it on mine and it's working fine on all bands.

B4 to B6 - ALC meter

The ALC meter seems to be very sensitive and with my MC-60A microphone,
in SSB, with volume at number 6 it saturates very easly.
But, I have found the factory values to work well. In my case, the values are:

B4 10 10 ALC MIN
B5 20 20 ALC MAX
B6 30 30 ALC.FULL

I have changed this, but I ended up by returning to the same values.
I haven't spent much time tweaking this and I will try it again in the near future because I am not happy yet with the ALC bar graph behaviour.

The service manual says that to adjust these values you do this (supose that we are adjusting B4): connect a 50 ohm dummy load into your antenna connection. Press [SEND] and the left number will vary and adjust itseld until it stops varying. Then you can press [UP] and move the result into the right side. Menu BA will save things.

Now, please notice the following. This 3 menus are hard to tweak and if you remove the microphone you will get different values.
When, at first, I changed this I tought that this was a "no way back" setup. After disliking my changes I wanted to go back to the original values and I strugled to find a way. Here it is: leave the 50 ohm dummy load on the antenna connection. Remove you microphone. Go to B4. For this one you want:

B4 10 10 ALC MIN.

Press [SEND] and slowly turn [MIC] until you have 10 on the left side.
This is a tricky adjustment because the number will keep on changing very quickly. When close to 10 try pressing [SEND] to stop TX and also to stop the number from changing. You may get a 10 on the left side.
If you went close to 10, try again.
After having 10, just press [UP] and it will go into the right side.

Now, you need 20 for B5:

B5 20 20 ALC MAX

I tryed to get 20 on B5 and I *allways* failed. So I went into B4 and I got 20 on the left side (same procedure has above). I *did not* press [UP] because I didn't want to mess up the B4 value.
I used [M.CH/VFO.CH] to change from B4 into B5. Guess what? The 20 value I had on B4 stayed there (on the left side) and went into B5. By pressing [UP] I updated [B5].

Now, try the same for [B6].

Also, on this menus, I am interested in your results.

B7 - SWR Protection

This item is very important because the value you choose here will trigger the SWR protection of the rig.
Changing this to a wrong value may cause the SWR protection to work to late (or not to work at all) and your rig will be transmiting into a high SWR. The consequences will be serious and you will ruin your finals (and who knows what else).
So *please* be carefull playing around with this.
Anyway, for the brave of heart, here is the info on how to change this.
From the factory, mine had this:

B7 1E 1E SWR PROT

Go into B7 and by using [RIT/XIT] you can vary the left number from 00 to FF (256 different levels).
Pressing [UP] will update the right number.
BA menu sabes your changes.

B8 - SWR meter

This will adjust your SWR meter. All 870s that I saw what swr meters that worked really well, so if your's is working fine leave this menu alone.
If not, try this: you will need a 150 ohm dummy load (yes, not 50 ohm, but 150 ohm). Hook up the dummy load to the rig. Go to B8 and press [SEND]. The left number will change. Pressing [UP] updates the right number and menu BA will save your changes.
*WARNING*: doing this with a 50 ohm dummy load will ruin you swr meter and will lead you to wrong swr readings (if you use this meter).

B9 - FM Deviation

Factory settings on several 870s seem to be:

B9 80 80 Fm DEV

Going into menu B9 and using the usual [RIT/XIT] button will change the left number. [UP] will update the right number. BA menu will save your changes.
To adjust this menu properly you need special test equipment, so I would advise you to stay away from this one.

BA - System

Refered many times before.
Usually:

BA Ready EEPROM

"Ready" means that you can record on the EEPROM.
Pressing [UP] will record *any* and *all* changed menus.
Reply after recording must be:

BA Good EEPROM

BB - Display

This will light up all the LCDs and all the leds on the rig.
You can check for a bad LCD or for not working leds.

So, this is it.
You can find more information on this menus on the TS-870S service manual. Look on page 92 and the following pages.
*I am allways* interested in learning more about this menus (and also other menus) on the 870.